How do you change the bulb on the back plate on 1990 cad eldorado?

To change the bulb on the back plate of a 1990 Cadillac Eldorado, first, ensure the vehicle is turned off and the keys are removed. Open the trunk and locate the access panel for the taillight assembly; you may need to remove screws or clips. Carefully pull the taillight assembly out, twist the bulb socket counterclockwise to remove it, replace the old bulb with a new one, then reassemble everything by reversing the steps. Make sure to test the new bulb before closing the access panel.